This update for jupyter-jupyterlab-server fixes the following issues:

Update to 1.2.0:

* Expose settings API to other handlers.
* Always wait for process to finish
* ensure the 'WHICH' command returns absolute path instead of relative path
* Clean up terminate logic
* Kill the subprocess if it does not stop
* Do not try to close the watch process file handle
* Update nodejs error message to not give an outdated version.
* Black and White Listings Handler
* Fix URL prefixing for absolute URLs